Summary: A review of visual memory capacity: Beyond individual
items and toward structured representations
Department of Brain and Cognitive Sciences,
Massachusetts Institute of Technology, USATimothy F. Brady
Department of Brain and Cognitive Sciences,
Massachusetts Institute of Technology, USATalia Konkle
Vision Sciences Laboratory, Department of Psychology,
Harvard University, USAGeorge A. Alvarez
Traditional memory research has focused on identifying separate memory systems and exploring different stages of
memory processing. This approach has been valuable for establishing a taxonomy of memory systems and characterizing
their function but has been less informative about the nature of stored memory representations. Recent research on visual
memory has shifted toward a representation-based emphasis, focusing on the contents of memory and attempting to
determine the format and structure of remembered information. The main thesis of this review will be that one cannot fully
understand memory systems or memory processes without also determining the nature of memory representations.
Nowhere is this connection more obvious than in research that attempts to measure the capacity of visual memory. We will
review research on the capacity of visual working memory and visual long-term memory, highlighting recent work that
emphasizes the contents of memory. This focus impacts not only how we estimate the capacity of the systemVgoing
beyond quantifying how many items can be remembered and moving toward structured representationsVbut how we
model memory systems and memory processes.
Keywords: memory, working memory, long-term memory, visual cognition, memory capacity, memory delity